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METHODS OF BREEDING.
IN-AND-IN BREEDING AMONG FAMILIES.
The term "in-and-in breeding" signifies the pairing of the nearest and nearer kin in one and the same family.
In-and-in breeding is the means of preserving unchanged, or cultivating the type of those two animals paired together at the beginning, for the reason that generally either animal transmits its peculiar qualities to its progeny, and this receives, by hereditary transmission, the qualities of both the parent animals. If the animals produced in this way, after reaching the state of maturity, are again paired exclusively with their sire or dam, and afterward the sisters and brothers, and so the following generations are again paired with one another, the original type of the stock animals must be preserved in a uniform manner, provided that external influences do not impede the growth and development of the animals.
By in-and-in breeding, if the new productions are consistently paired together, the tribe is produced, and nearly all tribes of recent times originated, or are originating in this way from a single one or several pairs. The celebrated breeder Bakewell, in founding his famous race of cattle, is said to have adopted and perfected the method of in-and-in breeding; the same plan was pursued by the brothers Collings
Although the pairing among members of families has great advantages, yet if the pairing of the nearest member of a family is continued through several generations, or for too great a period, and the animals are not selected with proper care, this system will be found to have correspond. ing disadvantages. The effects and the advantages and disadvantages of in-and-in breeding are, as yet, not fully understood, and therefore we shall enlarge somewhat on this subject. Sinclair, years ago, pointed out the advantages of in-and-in breeding, but he did not deny that if it was continued too long, imbecility and barrenness were the unavoidable consequences.
That in-and-in breeding among hogs causes a decrease in their prolificacy and a poor development in their offspring, has of late been shown especially in the breeding of English races; and still more recently Rhode, in his essay "on the nurture and use of the domestic hog,” (Greifswalde and Leipsic, 1860) says that the breeding of blood relations is very objectionable. A long continued pairing of the nearest members of families among sheep, has injurious effects, and it has even been considered to be the cause of the vertigo.
Nathusius adds to his monograph on "Shorthorn Cattle,” (Berlin, Bus. sellman, 1857) an appendix on in-and-in breeding, or pairing of near relations, in which he states the following points in regard to his system of breeding :
“The breeding with the nearest blood relations, especially among cattle, must often be re-adopted whenever it becomes necessary to establish certain qualities in breeding animals, and to produce higher degrees of improvement.
“But great precaution is required, because a long continued in-and-in breeding has often produced barrenness and debility in the offspring.
“In general, therefore, in and-in breeding should not be adopted in large herds, or among common working cattle, since among them such a minute observation of the individuals as the breeder of the improved race of ani. mals must exercise, would actually be impossible.”
Justinus, in his “Principles of Horse Breeding," says that those breed. ers are sadly mistaken who believe that unconditional in-and-in breeding produces more perfect animals, but, on the contrary, it becomes injurious if the breeding animals are defective. In respect to the in-and-in breeding of cattle, we append the following views :
David Low says, in his “Practical Agriculture,"—"This system has its limitation ; for nature will not conform to our combinations if they deviate too far from the usual way. It is a well-known fact that by the pairing of near relations, the volume of the bone decreases and fattening qualities in. crease; but on the other hand, the productions are much more delicate and subject to diseases. Therefore, if these combinations are continued with very excellent animals to a certain point, in order to insure constancy in the hereditary transmission of their qualities, we commit an act of violence against nature, if we go too far in this respect. The race possesses the advantages of early maturity and of fattening sooner and more easily ; but they lose their vigor and energy, the females do not give the requisite quantity of milk for nursing their young, and the males lose their procreative power and capability of propagating the race. Many breeders have sustained great losses by carrying in-and-in breeding too far, for the purpose of bringing a race to the culmination of perfection.
Settegast, in his paper “On Breeding," says: “The injurious consequences of in-and-in breeding are not so great and striking amorg cattle and horses as among hogs and sheep, but they must prove pernicious in the end."
H. von Nathusius, in his “Views on Breeding,” (Stockhardt's Agricul. taral Journal, 1838) says: “Where sach in-and-in breeding in families has been continued for many generations without any admixture of other blood, not even of the same race, some individuals, even of the same litter, will always be of greater, others of less value for use and breeding; nay, by an exclusive in-and-in breeding in families, if proper attention is not paid to a deviation from the general direct stream of blood, if no lateral branches, having for some time been bred in another direction, are taken in, it will often happen that the relative value of full sisters and brothers is the more unequal, and the hereditary transmission of their qualities the more insecure, the more the blood of the family has been preserved and concentrated.
Ed. Bawly, in an article “On the breeding of cattle,” (Wilda's Central Journal, 1858, vol. II.,) speaks as follows: "As to in-and-in-breeding among near relations, it undoubtedly is safer in regard to the production, but if contined for more than one or two generations it becomes objectionable, for although some greater perfection of form may be attained, yet the size will decrease and the constitution become debilitated.
John Sebright instituted experiments with different animals, and always found the disadvantages above mentioned recurring.
8. W. Von Pabst, in his "Instruction in the Breeding of Cattle," says: "Although we admit that animals faultless in every respect are often not found at all in the smaller tribes, and that the cause for hereditary defects are often overlooked in the beginning, yet there are many reasons why great precaution should be exercised in pairing near blood relations, especially in its repetition, and it should be avoided altogether, if this can be done without frustrating the purpose of breeding. Imust acknowledge that, in order to produce animals that would give the largest possible quantity of milk, I have repeatedly paired near blood relations, and, in doing 80, have not paid due attention to the somewhat neat frame of bones and narrow chest of the animals, paired together; the result was that I soon obtained productions of such a debilitated constitution as to fully convince me of the disadvantages of breeding among relations.
In order to show the analagous effects of sexual connections also between members of the human family of too near kin; two statements are presented. In Hasses' paper “On Suicides," it is stated: Among seventeen families whose parents were cousins to each other, there was one with five idiotic children, five with four each, three with three each, two with two each, and six with one each. These seventeen families bad altogether ninety-five children, of whom forty-four were idiotic, twelve scrofulous ad imbecile; in the whole, fifty-eight of a weak constitution and poor health. The French physician, Dr. Devay, says that among one hundred and twenty one marriages between blood relations of his acquaintance, no less than twenty-two were wholly barren; in seventeen cases the children
; had more than ten fingers, in two the small finger was lacking, in five others there were club feet, and in all the rest of three cases the state of health in these children was only tolerably good. The children of near blood relations are often deaf and dumb, they generally teeth later, and the development of their mind and body is retarded. The nearer the par ents are related together the worse are the consequences.
The cause of the degeneration of the offspring of animals by the pairing of near blood relations may be explained in the following way. Although the exterior of an animal may appear to be perfect, yet it may have a hidden defect or some disease in its organization. Frequently the members of a family show the same defects of forms which are hereditary, but less apparent in the individual. By pairing such blood relations the abnormity, although insignificant in the individual is thus doubled, obtains a double development in the offspring, and in this way the predisposition to disease or the disease itself originates. By breeding within families there is less probability that the imbecility of the one animal will be counter. balanced and equalized through the power or vigor of the other, or the excess on the one part through the deficiency on the other, than by pairing animals not related.
IN-AND-IN BREEDING AND THOROUGH BREEDING. Thorough breeding, in the strict signification of the term, signifies breeding among more distant relations, while in-and-in breeding among families means the pairing of near blood relations. Thorough breeding pairs ani.
. mals of a larger family or a breed, excluding any admixture of kindred breeds; as for instance the breeding together of the several families of the Short-horns. The German breeders make three systems of breeding, via: In breeding, in-and-in breeding, and pure breeding-their pure breeding is equivalent to our thorough breeding, as will be seen by the following paragraph:
“Pure breeding pairs the animal belonging to one tribe, excluding none of the several kinds of the same. This method of breeding, therefore, sims át preserving the purity of the tribe. Instance: the breeding be tween Montávon, Cloister Valley and Walser Valley cattle, the two latter being breeds of the Montavon tribe.”
The object of in-and-in and thorough breeding is the unchanged preservation of the properties of a breed or tribe of cattle which fully answer the purposes for which they are used. If the external influences-feeding, keeping, use, climate, &c., áre adapted to the nature of the tribe, those
two methods of breeding are the means of preserving the same in their principal type.
In-and-in breeding, as well as thorough breeding, may yet attain to å higher degree in this respect. But in-and-in or thorough breeding suo ceeds not only in preserving the tribe or breed unchanged and it also effects gradually an improvement of the animals in respect to their usefulness for the one or the other purpose or even for all purposes, and also in respect to form—thus an improvement in the true sense of the word; and likewise an increase of volume to a certain degree. If only the finest and largest specimens of cattle, which answer most fully the pur poses of the breeder in developing one or more useful qualities, are selected for breeding, and the inferior animals wholly excluded from breeding, and besides, if the feeding, keeping and use of the animals correspond exactly to those special purposes, the beauty, size, and usefulness of the tribe or breed may be improved álmost ad infinitum. In this way any, even the most inferior tribe of cattle, may be improved, without introducing strange male animals, &c., and without incurring the danger of injuring the tribe more or less by the admixture of new blood. If the people bave not ample means to invest in the breeding of cattle, and if the animals are bred, kept, and used according to correct principles, this method of breeding may be deemed preferable to the introduction of blood from other races, for the purpose of improving whole tribes of cattle.
Yet, in the face of these facts, some have declared in-and in and thorough breeding objectionable, contending that it leads inevitably to a depravation of the tribes or breeds. But this objection is wholly unfounded, if this system of breeding is pursued rationally; and if irrationally, this objeo tion does not apply to the system itself, but to the method in which it is executed. Of course, if breeding among near relations is carried on tó long, or if defective animals are continually paired together, the offspring must lose in vigor, perfection of form and usefulness, and the tribes rapidly degenerate by in-and-in or thorough breeding, and therefore such erroneous proceedings should be discontinued. The views just advanced is fully como roborated by Pabst in the following communication :
“As an instance of a long continued and very successful in-and-in breeding, I mention the fine tribe of the Gurten cattle, numbering at most twenty head, which for a long series of years has been established on the Royal stud farm of Kleinhohenheim, in which in-and-in breeding has been carried on at least during a period of forty years, and where the pairing of blood relatives was inevitable. This tribe is as powerful and useful to-day as when I first became acquainted with them, twenty-eight years ago; but faultless animals only were used for breeding." (Directions for the breeding of cattle.)